Metal-insulator-semiconductor (MIS) devices fabricated with mercury-cadmium-telluride (HgCdTe) or indiumantimonide (InSb) typically employ some form of surface passivation and a gate insulator. MIS devices often use a native oxide passivation in conjunction with a ZnS insulator, or a layer of SiO.sub.2, the SiO.sub.2 serving as both the passivation and insulator. The disadvantages of these HgCdTe and InSb devices include difficulties in controlling surface state densities, hysteresis effects and flat band instabilities which occur when these devices are exposed to moisture and/or ionic contaminants.
Other disadvantages inherent in the use of SiO.sub.2 passivation are unreliable mechanical properties such as poor adhesion, a susceptibility to ionic contamination which results in the aforementioned flat band instability, and manufacturing difficulties in the proper preparation of the HgCdTe or InSb surface prior to the deposition of the SiO.sub.2.